Internal-combustion engine



W@ Ty @n Q@ Q Q Q V5 a we Nm Nm Sv NW E. R. BURTNETT INTERNAL COMBUSTION ENGINE Filed July 16 i924 Patented Oct. 28, 1924.

UNITED STATES PATENT OFFICE.

EVERETT R. BURTNETT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR 0F ONE-HALF TO HOMER A. BRUNELL, OF LOS ANGELES, CALIFORNIA.

INTERNAL-COMBUSTION ENGINE.

Appflicaton filed `Tuly 16, 1924.

To all 'LU/wm, t may concern Be it known that l, Evnanr'r R. BURT- Nn'r'r, citizen o-f the United States, residing` at Los Angeles, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in lnternal-Combustion Engines, of which the following is a specification. v

My invention relates generally to internal combustion engines, and more particularly to engines of the two stroke cycle type wherein pumping cylinders are utilized for the precompression of gaseous fuel and for the forcing of said precompressed fuel into the combustion chambers.

The principal objects of my invention are to generally improve upon and simplify the construction of the existing forms of two stroke cycle engines, to provide an engine of the character'referred to having a plurality of combustion cylinders arranged in pairs with the members of each pair connected at their' head ends by a common clearance compression and combustion chamber, to arrange at one end of the cylinder block or row of cylinders a series of gaseous fuel pumping and precompression cylinders, the latter being connected by gaseous fuel trans-- fer ducts to the combustion cylinders.

As a result of my improved arrangement of cylinders and the connections between the pistons in` said cylinders and the 'crank shaft of the engine, the torque resulting from t-he expansion of the 4ignited gaseous fuel charges and the axial rocking couple of the combustion vunits are transmitted to the rear portion of the crank shaft and the pumping torque and couple developed within the pumping cylinders and their connections is transmitted to the forward portion of the crank shaft.

A further object of my invention is to provide in an engine of the character referred to a crank shaft having cranks arranged in proper angular positions to bring about the proper movements of the pistons within the cylinders, to provide said crank shaft with five bearings, and to equip the rear portion of said crank shaft with counterbalancing weights that tend to cause said crank shaft to operate with practically no vibration and without whip at all speeds, thereby insuring an even flow of power while the engine is in operation.

With the foregoing and other objects in Serial No. 726,322.

Figure 1 is a vertical section taken lengthy wise through the center of an engine of my improved construction;

Figure 2 is a diagrammatic view which graphically illustrates the relative positions of the cranks of the cra-nk shaft of my improved engine.

Referring by numerals to the accompanying drawings, 10 designates a cylinder block that is preferably formed with connected chambers 11 in its walls for the circulation of a fluid cooling medium, and formed in the rear portion of said block are six combustion chambers that are arranged in pairs, thereby forming practically three power units. Chambers 12 and 13, forming one pair, are arranged adjacent te the center ofthe block, chambers 14 and 15 forming the next pair being located to the rear of chambers 12 and 13, and the third pair of chambers 16 and 17 being located at the rear end of the block. Formed in the front portion of the block and in front of the pair of combustion -chambers 12 and 18 are three gaseous fuel pumping and precompression chambers 18, 19 and 20. All of the chambers just described are preferably arranged in a row with their aXes parallel.

Secured in any suitable manner on top of block 10 is a head block 21 having a chamber 22 through which may be circulated a fluid cooling medium, and formed in the under side of the front portion of this head block are three shallow recesses 23, 24 and 25 that coincide with and constitute compression clearance chambers for the gaseous fuel pumping and precompression chambers 18, 19 and 20, respectively.

Formed in the under side of the intermediate portion of head block 21 is a pocket or lrecess 26 that connects and provides a common clearance compression and combustion chamber for-the pair of combustion chambers 12 and 13. A similar chamber 27 that is formed in the .under side of the head .block 21 connects the head ends of comlil fi t) chamber 28 that is formed in the under side of the rear portion of head block 21 connects the head ends of chambers 16 and 17 and provides a common clearance compression and combustion chamber for said chambers 16 and 17. Seated in head block 21 and preferably at points above the combustion chambers 12, 14 and 16 are spark plugs 29, the terminals of the electrodes of which project, respectively, into the common clearance chambers 26, 27 and 28.

Leading from clearance chamber 23 above pumping chamber 18 to transfer inlet ducts 30 that are formed through the wall of block 10 and which communicate with the intermediate portion of combustion chamber 12 is a gaseous fuel transfer duct 31. A similar duct 32 leads Afrom the side of clearance chamber 24 above pumping chamber 19 to precompressed gaseous fuel inlet ports 33 that are formed through the wall of block 1() and which open into the intermediate portion of combustion chamber 14. A third precompressed gaseous fuel transfer duct 34 leads from the side ot' clearance chamber 25 above the pumping chamber 20 to the intermediate portion of combustion cha-1nber 16. Thus it will be seen that through the arrangement of the ducts just described pumping cylinder 18 at the front end of the engine block functions for the. power unit comprising the cylinders 12 and 13; pumping cylinder 19 functions Yfor the power unit comprising the cylinders 1.4 and l5; and the third pumping cylinder 2O functions for the unit comprising the cylinders 16 and 17.

Formed through the wall of cylinder block and at points intermediate the ends of the chambers 18, 19 and 29 are gaseous fuel' inlet ports, suoli as`35, that are connected to a suitable source of gaseous fuel supply, for instance a carinii-eter. Formed through 'the wall of block 10 and leading outwardly from the intermediate portions of the power unit combustion `chambers 13, and 17 are exhaust ports, such as 36. All of the ports just described are positioned so that they are wholly uncovered and open only when the pistons that operate `within the respective cylinders are at the lower to outer ends of 'their travel.

Block 10 surinounts a crank case member 37 and formed inthe end portions of the latter are bearings 38 for a crank shaft 39. y

Formed within this crank case member between pumping cylinder V and combustion cylinder 12 betwen the combustion cylinders 13' andV 14, and between the combustion cylinders 15 and 16 are bearings 40 for said crank shaft. Thus the crank shaft is pro vided with. ltive bearings, thereby insuring` minimum vibration during operation.

The forward portion of the crank shaft .is provided with three cranks or throws 41, 42 and 43, the same being arranged 120O apart, and said cranks being located, respeo tively, beneath or in line` with the axes of the pumping cylinders 1.8, 19 and 20. Pistons 44, 45 and 46 that are arranged for re ciprocation, .respectively, within chambers 18, 19 and 20 are connected by suitable connecting rods, such as 47, to the cranks 41, 42 and 43, respectively. Aarranged for reciprocatory movement within the combustion chambers 12 and 13 are pistons 48 and 49, respectively, said pistons being connected by suitable connecting rods, such as 50, vto crank 51 that 1s formed on crank shaft 39 to" axis of the crank shaft is an arm 52 on theft.

end of which is arranged a counterbalancingr weight crank 54 that is similar to crank 51 is arranged beneath or in line with .the combus-` tion chambers 14 and 15, and suitable con- -`i=' ne Jting rods 55 connect `said crank 54 with pistons 56 and 57 that are arranged, respectively, in the chambers 14- and 15. Projecting diametrically acrossv the axis of the crank shaft fromvthe center of crank 54 is a counterbalancing weight carrying arm 58.

A crank 60, similar to cranks 51 and 54, is arranged beneath cylinders 16 and 17, and the pistons 61 and 62 that are arranged, resjiectivcly, in said chambers 16 and 17 are connected to said crank 60 by suitable connecting rods 63. Projecting from the centrai portion ot crank 60 diametrically across the axis of the crank shaft is a counterbalancinpl weight carrying arm 64.

Cranks 51. 54 and 60 are arrangedlQOO apart, and with respect to cranks 41, 42 and 43 crank 51 is arranged diametrically opfposite or 1800 from crank 41; crank 54 is located diametrically oppositeor 180 from crank 42; and crank 60 is located diametrically opposite or 180o from crank 43 (sec Figure 2).

a result of this crank arrangement7 the pistons 48 and 49 in combustion cylinders 12 and 13 travel simultaneously with and directly opposite to pumping piston 44, and this action is also true ofl pistons 56 and 57 in the combustion cylinders 14 and 15, and

pumping piston 45, and likewise thepistons 61 and 62 in combustion cylinders 16 and 17v and the pumping piston 46. As each pumping piston approaches and passes low center, the corresponding gaseous fuel inlet ports are uncovered', thereby admittinga charge ofgaseou's fuel, and on the upward or inward stroke of the pumping piston, this gaseous fuel' charge is compressed in the corresponding clearance chamber in the head blockand in the-transfer duct leading lll?) from said clearance chamber. As each pair of pistons within the combustion chambers approach and pass their low centers, the corresponding precompressed gaseous fuel inlet ports and exhaust ports are simultaneously opened, thereby admitting a charge of precompressed gaseous fuel into the first chambers of each pair, and the in-rush of this fuel charge lupwardly through the chamber into which the precompressed fuel is admitted and thence through the common clearance chamber in the head block and thence downwardly through the rear chamber of each pair to the exhaust ports leading therefrom effects a discharge of the products of combustion remaining in the connected combustion chambers from the previously ignited fuel charge.

On the succeeding upward stroke of the pair of pistons within the combustions chambers to which the precompressed fuel charge was admitted, as just described, said gaseous fuel will be compressed in the upper portions of the connected chambers and in the common clearance chamber therefor. As each pair of combustion pistons pass their high centers or immediately thereafter7 the compressed gaseous fuel charge in the common clearance chamber above said pistons will be ignited by a spark produced between the terminals of the electrodes of the corresponding spark plug, and the expansion following combustion of the cha-rge thus ignited will force the pistons downward or outward on their power stroke. Inasmuch as the cranks that are associated with the three power units of the engine, which power units comprise the three pairs of connected combustion chambers, are arranged 120o apart, the crank shaft receives three power impulses during each revolution, thereby insuring a practically even fiow of power output, andas the three cranks for the three power units form the rear portion of the crank shaft, said rear portion will receive all the expansion torque and axial rocking couple that is developed in the engine during operation. Inasmu-ch as three pumping cylinders are arranged at the forward end of the engine and in front of the power units, the pumping torque and couple will be impressed only upon the forward portion of the crank shaft or that portion to which the pistons within the pumping cylinders are connected. A

The arrangement of five main bearings for the crank shaft, the relative angular arrangement of the cranks of said shaft, the

y relative positions of the pumping cylinders with respect to the series of cylinders forming the power units, and the counterbalancing of that portion of the crank shaft to which the wer units are connected, all combine an cooperate to eliminate vibration in the crank shaft during operation and o enhance the smooth. running action of the engine.

It will be understod that minor changes in the size, form and construction of my improved two stroke cycle internal combustion engine may be made without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

l. In a two stroke cycle internal com-y bustion engine, three power units, each of which comprises a pair of combustion cylinders connected at their head ends by a common clearance chamber, a series of three pumping cylinders arranged in front of and in row with the cylinders forming the power units, and means whereby each pumping cylinder functions for the precompression and pumping of gaseous fuel into one cylinder of each pair of connected combus^` tion cylinders.

2. In a two stroke cycle internal combustion engine, three power units, each of which comprises a pair of `combustion cylinders conne-:ted at their head ends by a common clearance chamber, a series of three pumping cylinders arranged in front of and in row with the cylinders forming the power units, means whereby each pumping cylinder functions for the precompression and pumping of gaseous fuel into one cylinder oteach pair of connected combustion cylinders, pistons arranged for operation within all of the cylinders, a crank shaft to which said pistons are connected, the cranks to which the pistons in the pumping cylinders are connected being arranged 1200 apart, and the cranks to which the pistons of the power units are connected being arranged 120 apart.

3. In a two stroke cycle internal combustion engine, three power units, each of which comprises a pair of combustion cylinders connected at their head ends by a common clearance chamber, a series of three pumping cylinders arranged in front of and in row with the cylinders forming the power units, means whereby each pumping cylinder functions. for the precompression and pumping of gaseous fuel into one cylinder of each pair of connected combustion cylinders, pistons arranged for operation within all of the cylinders, crank shaft to which said pistons are connected, the cranks to which the pistons in the pumping cylinders are connected being arranged 120o apart, the cranks to which the pistons of the power units are connected being arranged 120 apart, and the respective cranks for the pistons of the power units occupying radial planes that are diametrically opposite or 180 from the corresponding cranks for the pistons in the pumping cylinders.

4. In a two stroke cycle internal combustion engine, a plurality of combustion llf) cylinders' arranged in pairs with the members of each pair connected at their head ends by a common clearance chamber, a series of pumping cylinders arranged in front of and in row with the combustion cylinders, a precompressed gaseous fuel duct leading from the inner end of each pumping'cylinder to one of the combustion cylinders of each pair, and the other cylinder of earch pair of combustion chambers being provided with an exhaust port.

5. In a two stroke cycle internal combustion engine, a plurality of combustion cylinders arranged'in pairs with the members of each pair connected at their head ends by a common clearance chambers, a series. of pumping cylinders arranged in front of and in row with the combustion oylinders,a precompressed gaseous fuel duct leading from the inner end of each pumping cylinder to one of the combustion cylinders of each pair, the other cylinder of each pair of combustion-chambers being provided with an exhaust port, pistons arranged for operation within all of the cylinders, and a crank shaft to which all` of said pistons. are connected.

6. In a two stroke cycle internal combustion engine, aI plurality of combustion lcylinders arranged in` pairs With the members of each pair connected at their head ends by' a common clearance chamber, a series of pumping cylinders arranged in front of and in row With the combustion cylinders, a precompressed gaseous fuel duct leading from the inner end of each pumping cylinder to one of the combustion cylinders of each pair, the other cylinder of each pair of combustion chambers being provided with an exhaust port, pistons arranged for operation Within all of the cylinders, a crank shaft to which all of said pistons are connected, and counterbalancing means yarranged on those cranks of said crank shaft to whichy the pistons within the combustion chambers are connected.

7. In a two stroke cycle internal comw bustion engine, a series of cylind' s arranged in" row, certain of the cylin ers at one end of the row functioning as gaseous fuel precompression and pumping cylinders, the remaining cylinders in the row bein arranged in pairs with the members of eac pair connected at their head ends by a` common clearance chamber, said pairs ofl connectedl cylinders functioning as combustion cylinders,.and which are served by the pumping cylinders at the end of the row, pistons arranged for operation Within all of said cylinders, and a crank shaft to Which all of said pistons are connected.

8. In a tivo stroke cycleinternal con bustion engine, a series of cylinders arranged in row, certain of the cylinders at one end ofthe roW functioning as gaseous fuel precompressionv and pumping cylinders, the remaining cylinders in the row being arranged in pairs with the members of each pair connected at their head ends by a common clearance chamber, said pairs of connected cylinders functioning as combustion cylinders, and which are served by the pumping cylinders at the end ofthe row, pistons arranged for operation Within all of said cylinders, a crank shaft to which all of said pistons are connected, and five main bearings for said crank shaft.

In testimony whereof I aix my signature.

InvnnETT R. BURTNETT. 

